eg buy a cheap second hand phone but rather than mounting it to the bike as in that thread, just use it with wifi/bluetooth/data/brightness/etc all turned off which considerably extends the run time of the phone.

I’m getting sick of my phone dying when recording rides so I was thinking about getting something solely for GPS use. I only want something to record my ride, nothing else. And as cheap as possible really.

Is there nothing cheaper than the Garmin Edge 200 or Bryton Rider 20, because the Garmin is £90 and the Bryon £75.

I use a Garmin 200 and its great for what I want. The breadcrumb trails are much better than people credit and are easy to follow. Battery life is pretty good, easily enough for 10 hours on the bike, doesnt lose its signal in forests and they have two brackets so you can swop between bikes.